Body mass index from the RE-LY trial: further evidence of the obesity paradox

Background

The obesity paradox has been reported in 3 post-hoc analyses evaluating the direct oral anticoagulants (DOAC) against warfarin (W): apixaban (ARISTOTLE), rivaroxaban (ROCKET), and edoxaban (ENGAGE-AF).

Purpose

To evaluate the obesity paradox in a post-hoc analysis of the RE-LY trial, comparing dabigatran 110 mg BID (D110), 150 mg BID (D150), and W by body mass index (BMI).

Methods

Baseline characteristics were evaluated using World Health Organization (WHO) criteria of overweight and obese (BMI ≥25 kg/m2) and under and normal weight (BMI <25 kg/m2). Stroke and systemic embolism, ischemic stroke, major bleeding, mortality, and intracranial hemorrhage were evaluated using BMI as a continuous variable and by the WHO criteria using a cox proportional hazard model.

Results

BMI was available in 99.9% of patients randomized; 74% had a BMI ≥25. At baseline, patients with a BMI ≥25 were younger (70.9 vs 73.1, p<0.001) and had fewer prior strokes (11.5% vs 15.6%, p<0.001), but higher mean creatinine clearance (78.3 vs 57.0, p<0.001) and rates of diabetes (25.8% vs 16.1%, p<0.001) (Table 1). Independent of drug assignment, patients with a BMI ≥25 had lower rates of stroke and systemic embolism (HR 0.65 [95% CI 0.54–0.79], p<0.001), ischemic stroke (0.75 [95% CI 0.60, 0.94], p=0.01), major bleeding (HR 0.79 [95% CI 0.69,0.89], p<0.001), mortality (HR 0.60 [95% CI 0.53, 0.67], p<0.001) and intracranial hemorrhage (HR 0.53 [95% CI 0.38, 0.73], p<0.001) compared to those with a BMI <25. Using BMI as a continuous variable combining all outcomes at 3 years, endpoint rates declined as BMI approached 25 in all 3 treatment groups. The exceptions were intracranial hemorrhage for D110 and D150 and stroke in D150 patients, where rates were low independent of BMI. No significant interaction between BMI and treatment was observed in individual outcomes except for the D110 vs. D150 comparison for major bleeding, in favor of D110 for patients with BMI ≥25 (HR 0.77 [95% CI 0.65, 0.91] and HR 1.12 [95% CI 0.86, 1.47], interaction p=0.0190).

Conclusions

In RE-LY, independent of drug assignment, patients with a higher BMI had improved outcomes, demonstrating the obesity paradox. As BMI increased towards 25, outcome rates improved except for intracranial hemorrhage rates for both D110 and D150 and ischemic stroke rates for D150, which were low independent of BMI. Patients treated with D110 with a BMI ≥25 kg/m2 had significantly lower rates of bleeding compared to D150.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Sharpe Strumia Foundation

Consequences of applying the new EWGSOP2 guideline instead of the former EWGSOP guideline for sarcopenia case finding in older patients

INTRODUCTION

we examined the consequences of applying the new EWGSOP2 algorithm for sarcopenia screening instead of the former EWGSOP algorithm (EWGSOP1) in geriatric inpatients.

METHODS

the dataset of our formerly published Sarcopenia in Geriatric Elderly (SAGE) study includes 144 geriatric inpatients (86 women, 58 men, mean age 80.7±5.6 years) with measurements of gait speed, handgrip strength and appendicular muscle mass by dual x-ray absorptiometry (DXA). We analysed the agreement between EWGSOP and EWGSOP2 algorithms in identifying patients as sarcopenic/non-sarcopenic. Differences in the distribution sarcopenic vs. non-sarcopenic were assessed by Chi²-test.

RESULTS

sarcopenia prevalence according to EWGSOP1 (41 (27.7%)) was significantly higher than with EWGSOP2 (26(18.1%), p<0.05). The sex-specific sarcopenia prevalence was 22.1% (EWGSOP1) and 17.4% (EWGSOP2), respectively, for women (difference not significant) and 37.9% vs. 19.4% for men (p<0.05%). The overall agreement in classifying subjects as sarcopenic/non-sarcopenic was 81.25% (81.4% for women, 81.0% for men). However, among the 41 sarcopenia cases identified by EWGSOP1, only 20 (48.8%) were diagnosed with sarcopenia by EWGSOP2 (9/19 w (47.4%), 11/22 m (50.0%)). Ten of 19 women (52.6%) and 11 of 22 men (50.0%) diagnosed with sarcopenia by EWGSOP1 were missed by EWGSOP2, while 6 of 15 women (40.0%) and 0 of 11 men (0.0%) were newly diagnosed.

DISCUSSION

there is a substantial mismatch in sarcopenia case finding according to EWGSOP1 and EWGSOP2. The overall prevalence and the number of men diagnosed with sarcopenia are significantly lower in EWGSOP2. While the absolute number of women identified as sarcopenic remains relatively constant, the overlap of individual cases between the two definitions is low.

Molybdenum cofactor deficiency type B knock-in mouse models carrying patient-identical mutations and their rescue by singular AAV injections

Molybdenum cofactor deficiency is an autosomal, recessively inherited metabolic disorder, which, in the absence of an effective therapy, leads to early childhood death due to neurological deterioration. In type A of the disease, cyclic pyranopterin monophosphate (cPMP) is missing, the first intermediate in the biosynthesis of the cofactor, and a biochemical substitution therapy using cPMP has been developed. A comparable approach for type B of the disease with a defect in the second step of the synthesis, formation of molybdopterin, so far has been hampered by the extreme instability of the corresponding metabolites. To explore avenues for a successful and safe gene therapy, knock-in mouse models were created carrying the mutations c.88C>T (p.Q30X) and c.726_727delAA, which are also found in human patients. Recombinant adeno-associated viruses (rAAVs) were constructed and used for postnatal intrahepatic injections of MoCo-deficient mice in a proof-of-concept approach. Singular administration of an appropriate virus dose in 60 animals prevented the otherwise devastating phenotype to a variable extent. While untreated mice did not survive for more than 2 weeks, some of the treated mice grew up to adulthood in both sexes.

Functional analysis of the p.[Arg74Trp;Val201Met;Asp1270Asn]/p.Phe508del CFTR mutation genotype in human native colon

Background

The impact of complex alleles on CFTR processing and function has yet not been investigated in native human tissue.

Methods

Intestinal current measurements (ICM) followed by CFTR immunoblot were performed on rectal biopsies taken from two siblings who are compound heterozygous for the CFTR mutations p.Phe508del and the complex allele p.[Arg74Trp;Val201Met;Asp1270Asn].

Results

Normal and subnormal chloride secretory responses in the ICM were associated with normal and fourfold reduced amounts of the mature glycoform band C CFTR, respectively, consistent with the unequal clinical phenotype of the siblings.

Conclusion

The combined use of bioassay and protein analysis is particularly meaningful to resolve the CFTR phenotype of “indeterminate” borderline CFTR genotypes on a case‐to‐case basis.

A mild case of molybdenum cofactor deficiency defines an alternative route of MOCS1 protein maturation

Molybdenum cofactor deficiency is an autosomal recessive inborn error of metabolism, which results from mutations in genes involved in Moco biosynthesis. Moco serves as a cofactor of several enzymes, including sulfite oxidase. MoCD is clinically characterized by intractable seizures and severe, rapidly progressing neurodegeneration leading to death in early childhood in the majority of known cases. Here we report a patient with an unusual late disease onset and mild phenotype, characterized by a lack of seizures, normal early development, a decline triggered by febrile illness and a subsequent dystonic movement disorder. Genetic analysis revealed a homozygous c.1338delG MOCS1 mutation causing a frameshift (p.S442fs) with a premature termination of the MOCS1AB translation product at position 477 lacking the entire MOCS1B domain. Surprisingly, urine analysis detected trace amounts (1% of control) of the Moco degradation product urothione, suggesting a residual Moco synthesis in the patient, which was consistent with the mild clinical presentation. Therefore, we performed bioinformatic analysis of the patient's mutated MOCS1 transcript and found a potential Kozak-sequence downstream of the mutation site providing the possibility of an independent expression of a MOCS1B protein. Following the expression of the patient's MOCS1 cDNA in HEK293 cells we detected two proteins: a truncated MOCS1AB protein and a 22.4 kDa protein representing MOCS1B. Functional studies of both proteins confirmed activity of MOCS1B, but not of the truncated MOCS1AB. This finding demonstrates an unusual mechanism of translation re-initiation in the MOCS1 transcript, which results in trace amounts of functional MOCS1B protein being sufficient to partially protect the patient from the most severe symptoms of MoCD.

Improving physical and mental health in frontline mental health care providers: Yoga-based stress management versus cognitive behavioral stress management

The need for brief, low-cost, easily disseminable and effective interventions to promote healthy lifestyles is high. This is especially true for mental health providers. We developed two studies to compare the impacts of Cognitive Behavioral Stress Management (CBSM) and Yoga Based Stress Management (YBSM) interventions for healthcare professionals. Study 1 offered an 8-week YBSM intervention to 37 mental healthcare participants and collected health data pre and post. Study 2 offered YBSM and CBSM classes to 40 randomly assigned mental healthcare providers and collected mental and physical health data at four time points. In Study 1, using t-tests, the YBSM intervention affected a number of mental and physical wellbeing indices pre to post. In Study 2, using linear mixed modeling, both YBSM and CBSM groups improved significantly (p <.05) in fruit and vegetable intake, heart rate, alcohol consumption, relaxation and awareness, professional quality of life, compassion satisfaction, burnout, depression, and stress levels. There was a group by time effect for coping confidence (CBSM increased more, p<.05, F = 4.34), physical activity (YBSM increased more, p<.05, F = 3.47), overall mental health (YBSM increased more, p<.10, F =5.32), and secondary traumatic stress (YBSM decreased more, p<.10, F = 4.89). YBSM and CBSM appear to be useful for healthcare professionals' mental and physical health. YBSM demonstrates some benefit above and beyond the extremely well-studied and empirically supported CBSM, including increased physical activity, overall mental health, and decreased secondary traumatic stress benefits.

Chronological changes of the amplitude-integrated EEG in a neonate with molybdenum cofactor deficiency

Molybdenum cofactor (Moco) deficiency is a rare neurometabolic disorder, characterized by neurological impairment and refractive seizures, due to toxic accumulation of sulfite in the brain. Earlier it was suggested that in Moco-deficient humans maternal clearance of neurotoxic metabolites prevents prenatal brain damage. However, limited data are available about the time profile in which neurophysiologic deterioration occurs after birth. The amplitude-integrated electroencephalography (aEEG) is a bedside method in neonates to monitor cerebral recovery after hypoxic-ischemic insults, detect epileptic activity, and evaluate antiepileptic drug treatment. We describe a chronological series of changes in aEEG tracings in a neonate with Moco deficiency. He presented with myoclonic spasms and hypertonicity a few hours after birth, however, the aEEG pattern was still normal. Within 2 days, the aEEG rapidly changed into a burst suppression pattern with repetitive seizures. After antiepileptic treatment, the aEEG remained abnormal. In this patient, the normal aEEG pattern at birth may have been due to maternal clearance of sulfite in utero. After birth, accumulation of sulfite causes progressive brain damage, reflected by the progressive depression of the aEEG tracings. This is in agreement with the results from a Moco-deficient mouse model, suggesting that maternal sulfite clearance suppresses prenatal brain damage. To our knowledge, this is the first case report describing the chronological changes in the aEEG pattern in a Moco-deficient patient. Insight into the time profile in which neurologic deterioration in Moco-deficient humans occurs is essential, especially when potential treatment strategies are being evaluated.

Functional deficiencies of sulfite oxidase: Differential diagnoses in neonates presenting with intractable seizures and cystic encephalomalacia

Sulfite oxidase is a mitochondrial enzyme encoded by the SUOX gene and essential for the detoxification of sulfite which results mainly from the catabolism of sulfur-containing amino acids. Decreased activity of this enzyme can either be due to mutations in the SUOX gene or secondary to defects in the synthesis of its cofactor, the molybdenum cofactor. Defects in the synthesis of the molybdenum cofactor are caused by mutations in one of the genes MOCS1, MOCS2, MOCS3 and GEPH and result in combined deficiencies of the enzymes sulfite oxidase, xanthine dehydrogenase and aldehyde oxidase. Although present in many ethnic groups, isolated sulfite oxidase deficiency and molybdenum cofactor deficiency are rare inborn errors of metabolism, which makes awareness of key clinical and laboratory features of affected individuals crucial for early diagnosis. We report clinical, radiologic, biochemical and genetic data on a Brazilian and on a Turkish child with sulfite oxidase deficiency due to the isolated defect and impaired synthesis of the molybdenum cofactor, respectively. Both patients presented with early onset seizures and neurological deterioration. They showed no sulfite oxidase activity in fibroblasts and were homozygous for the mutations c.1136A>G in the SUOX gene and c.667insCGA in the MOCS1 gene, respectively. Widely available routine laboratory tests such as assessment of total homocysteine and uric acid are indicated in children with a clinical presentation resembling that of hypoxic ischemic encephalopathy and may help in obtaining a tentative diagnosis locally, which requires confirmation by specialized laboratories.

Successful treatment of molybdenum cofactor deficiency type A with cPMP

Molybdenum cofactor deficiency (MoCD) is a rare metabolic disorder characterized by severe and rapidly progressive neurologic damage caused by the functional loss of sulfite oxidase, 1 of 4 molybdenum-dependent enzymes. To date, no effective therapy is available for MoCD, and death in early infancy has been the usual outcome. We report here the case of a patient who was diagnosed with MoCD at the age of 6 days. Substitution therapy with purified cyclic pyranopterin monophosphate (cPMP) was started on day 36 by daily intravenous administration of 80 to 160 microg of cPMP/kg of body weight. Within 1 to 2 weeks, all urinary markers of sulfite oxidase (sulfite, S-sulfocysteine, thiosulfate) and xanthine oxidase deficiency (xanthine, uric acid) returned to almost normal readings and stayed constant (>450 days of treatment). Clinically, the infant became more alert, convulsions and twitching disappeared within the first 2 weeks, and an electroencephalogram showed the return of rhythmic elements and markedly reduced epileptiform discharges. Substitution of cPMP represents the first causative therapy available for patients with MoCD. We demonstrate efficient uptake of cPMP and restoration of molybdenum cofactor-dependent enzyme activities. Further neurodegeneration by toxic metabolites was stopped in the reported patient. We also demonstrated the feasibility to detect MoCD in newborn-screening cards to enable early diagnosis.

AAV-mediated gene therapy for metabolic diseases: dosage and reapplication studies in the molybdenum cofactor deficiency model

In a mouse model for molybdenum cofactor deficiency as an example for an inherited metabolic disease we have determined the dosage of recombinant AAV necessary to rescue the lethal deficiency phenotype. We demonstrated long-term expression of different expression cassettes delivered in a chimeric AAV capsid of serotype 1/2 and compared different routes of application. We then studied the effect of double and triple injections at different time points after birth and found a short neonatal window for non-response of the immune system. Exposition with rAAV capsids within this window allows transgene expression after a second rAAV transduction later. However, exposition within this window does not trigger immunotolerance to the viral capsid, which limits rAAV-mediated refurbishment of the transgene to only one more application outside this permissive window.

Adolescent Transition to Adult Care in Solid Organ Transplantation: a consensus conference report

Transition of care from pediatric to adult-oriented health care providers is difficult for children with special health care needs. Children who have received solid organ transplants and their providers experience the same difficulties and frustrations as children with other major illnesses. A consensus conference was organized by several transplant organizations to identify major issues in this area and recommend possible approaches to easing the process of transition for solid organ transplant recipients. This report summarizes the discussions and recommendations.

Cranial ultrasound and chronological changes in molybdenum cofactor deficiency

Molybdenum cofactor is essential for the function of three human enzymes: sulphite oxidase, xanthine dehydrogenase, and aldehyde oxidase. Molybdenum cofactor deficiency is a rare autosomal recessively inherited disease. Disturbed development and damage to the brain may occur as a result of accumulation of toxic levels of sulphite. The CT and MRI findings include severe early brain abnormalities and have been widely reported, but the cranial US imaging findings have seldom been reported. We report a chronological series of cranial US images obtained from an affected infant that show the rapid development of cerebral atrophy, calcifications and white matter cysts. Our report supports the utility of cranial US, a noninvasive bed-side technique, in the detection and follow-up of these rapidly changing lesions.

Long-term rescue of a lethal inherited disease by adeno-associated virus-mediated gene transfer in a mouse model of molybdenum-cofactor deficiency

Molybdenum cofactor (MoCo) deficiency is a progressive neurological disorder that inevitably leads to early childhood death because of the lack of any effective therapy. In a mouse model of MoCo deficiency type A, the most frequent form of this autosomal recessively inherited disease, the affected animals show the biochemical characteristics of sulphite and xanthine intoxication and do not survive >2 wk after birth. We have constructed a recombinant-expression cassette for the gene MOCS1, which, via alternative splicing, facilitates the expression of the proteins MOCS1A and MOCS1B, both of which are necessary for the formation of a first intermediate, cyclic pyranopterin monophosphate (cPMP), within the biosynthetic pathway leading to active MoCo. A recombinant adeno-associated virus (AAV) vector was used to express the artificial MOCS1 minigene, in an attempt to cure the lethal MOCS1-deficient phenotype. The vector was used to transduce Mocs1-deficient mice at both 1 and 4 d after birth or, after a pretreatment with purified cPMP, at 40 d after birth. We report here that all Mocs1-deficient animals injected with a control AAV-enhanced green fluorescent protein vector died approximately 8 d after birth or after withdrawal of cPMP supplementation, whereas AAV-MOCS1-transduced animals show significantly increased longevity. A single intrahepatic injection of AAV-MOCS1 resulted in fertile adult animals without any pathological phenotypes.

A novel MOCS2 mutation reveals coordinated expression of the small and large subunit of molybdopterin synthase

The small and large subunits of molybdopterin (MPT) synthase (MOCS2A and MOCS2B), are both encoded by the MOCS2 gene in overlapping and shifted open reading frames (ORFs), which is a highly unusual structure for eukaryotes. Theoretical analysis of genomic sequences suggested that the expression of these overlapping ORFs is facilitated by the use of alternate first exons leading to alternative transcripts. Here, we confirm the existence of these overlapping transcripts experimentally. Further, we identified a deletion in a molybdenum cofactor deficient patient, which removes the start codon for the small subunit (MOCS2A). We observed undisturbed production of both transcripts, while Western blot analysis demonstrated that MOCS2B, the large subunit, is unstable in the absence of MOCS2A. This reveals new insights into the expression of this evolutionary ancient anabolic system.

Ten novel mutations in the molybdenum cofactor genes MOCS1 and MOCS2 and in vitro characterization of a MOCS2 mutation that abolishes the binding ability of molybdopterin synthase

Molybdenum cofactor deficiency (MIM#252150) is a severe autosomal-recessive disorder with a devastating outcome. The cofactor is the product of a complex biosynthetic pathway involving four different genes (MOCS1, MOCS2, MOCS3 and GEPH). This disorder is caused almost exclusively by mutations in the MOCS1 or MOCS2 genes. Mutations affecting this biosynthetic pathway result in a lethal phenotype manifested by progressive neurological damage via the inactivation of the molybdenum cofactor-dependent enzyme, sulphite oxidase. Here we describe a total of ten novel disease-causing mutations in the MOCS1 and MOCS2 genes. Nine out of these ten mutations were classified as pathogenic in nature, since they create a stop codon, affect constitutive splice site positions, or change strictly conserved motifs. The tenth mutation abolishes the stop codon of the MOCS2B gene, thus elongating the corresponding protein. The mutation was expressed in vitro and was found to abolish the binding affinities of the large subunit of molybdopterin synthase (MOCS2B) for both precursor Z and the small subunit of molybdopterin synthase (MOCS2A).

The pathogenesis of molybdenum cofactor deficiency, its delay by maternal clearance, and its expression pattern in microarray analysis

Molybdenum cofactor (Moco)-deficiency is a lethal autosomal recessive disease, for which until now no effective therapy is available. The biochemical hallmark of this disorder is the inactivity of the Moco-dependent sulfite oxidase, which results in elevated sulfite and diminished sulfate levels throughout the organism. In humans, Moco-deficiency results in neurological damage, which is apparent in untreatable seizures and various brain dysmorphisms. We have recently described a murine model for Moco-deficiency, which reflects all enzyme and metabolite changes observed in the patients, and an efficient therapy using a biosynthetic precursor of Moco has been established in this animal model. We now analyzed these mice in detail and excluded morphological brain damage, while expression analysis with microarrays indicates a massive cell death program. This neuronal damage appears to be triggered by elevated sulfite levels and is ameliorated in affected embryos by maternal clearance.

Possible association of mitochondrial transcription factor A (TFAM) genotype with sporadic Alzheimer disease

Mitochondrial transcription factor A (TFAM) is essential for transcription and replication of mammalian mitochondrial DNA (mtDNA). Disturbance of maintenance of mtDNA integrity or mitochondrial function may underlay neurodegenerative disorders such as Alzheimer disease (AD). TFAM, the gene encoding TFAM maps to chromosome 10q21.1, a region that showed linkage to late-onset AD in several study samples. We screened TFAM for single nucleotide polymorphisms (SNPs) and genotyped the G>C SNP rs1937, coding for S12T in mitochondrial signal sequence of TFAM, and the A>G SNP rs2306604 (IVS4+113A>G) in 372 AD patients and 295 nondemented control subjects. There was an association of genotype rs1937G/G with AD in females and an association of a TFAM haplotype with AD both in the whole sample and in females. The findings suggest that a TFAM haplotype containing rs1937 G (for S12) may be a moderate risk factor for AD.

Rescue of lethal molybdenum cofactor deficiency by a biosynthetic precursor from Escherichia coli

Substitution therapies for orphan genetic diseases, including enzyme replacement methods, are frequently hampered by the limited availability of the required therapeutic substance. We describe the isolation of a pterin intermediate from bacteria that was successfully used for the therapy of a hitherto incurable and lethal disease. Molybdenum cofactor (Moco) deficiency is a pleiotropic genetic disorder characterized by the loss of the molybdenum-dependent enzymes sulphite oxidase, xanthine oxidoreductase and aldehyde oxidase due to mutations in Moco biosynthesis genes. An intermediate of this pathway-'precursor Z'-is more stable than the cofactor itself and has an identical structure in all phyla. Thus, it was overproduced in the bacterium Escherichia coli, purified and used to inject precursor Z-deficient knockout mice that display a phenotype which resembles that of the human deficiency state. Precursor Z-substituted mice reach adulthood and fertility. Biochemical analyses further suggest that the described treatment can lead to the alleviation of most symptoms associated with human Moco deficiency.

Association of late-onset Alzheimer disease with a genotype of PLAU, the gene encoding urokinase-type plasminogen activator on chromosome 10q22.2

Urokinase-type plasminogen activator (uPA) converts plasminogen to plasmin. Plasmin is involved in processing of amyloid precursor protein and degrades secreted and aggregated amyloid-beta, a hallmark of Alzheimer disease (AD). PLAU, the gene encoding uPA, maps to chromosome 10q22.2 between two regions showing linkage to late-onset AD (LOAD). We genotyped a frequent C/T single nucleotide polymorphism in codon 141 of PLAU (P141L) in 347 patients with LOAD and 291 control subjects. LOAD was associated with homozygous C/C PLAU genotype in the whole sample (chi2=15.7, P=0.00039, df 2), as well as in all sub-samples stratified by gender or APOE epsilon4 carrier status (chi2> or = 6.84, P< or =0.033, df 2). Odds ratio for LOAD due to homozygosity C/C was 1.89 (95% confidence interval 1.37-2.61). PLAU is a promising new candidate gene for LOAD, with allele C (P141) being a recessive risk allele or allele T (L141) conferring protection.

Mutations in the molybdenum cofactor biosynthetic genes MOCS1, MOCS2, and GEPH

Molybdenum cofactor deficiency in humans results in the loss of the activity of molybdoenzymes sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase. The resultant severe phenotype, which includes progressive neurological damage leading in most cases to early childhood death, results primarily from the deficiency of sulfite oxidase. All forms of molybdenum cofactor deficiency are inherited as autosomal recessive traits. The cofactor is an unstable reduced pterin with a unique four-carbon side chain, synthesized by a complex pathway that requires the products of at least four different genes (MOCS1, MOCS2, MOCS3, and GEPH). Disease-causing mutations have been identified in three of these genes: MOCS1, MOCS2, and GEPH. MOCS1 and MOCS2 have a bicistronic architecture; i.e., each gene encodes two proteins in different open reading frames. The protein products, MOCS1A and B and MOCS2A and B, are expressed either from different mRNAs generated by alternative splicing or by independent translation of a bicistronic mRNA. The gephyrin protein, encoded by a third locus, is required during cofactor assembly for insertion of molybdenum. A total of 32 different disease-causing mutations, including several common to more than one family, have been identified in molybdenum cofactor-deficient patients and their relatives.

Computerisation and decision making in neonatal intensive care: a cognitive engineering investigation

This paper reports results from a cognitive engineering study that looked at the role of computerised monitoring in neonatal intensive care. A range of methodologies was used: interviews with neonatal staff, ward observations, and experimental techniques. The purpose was to investigate the sources of information used by clinicians when making decisions in the neonatal ICU. It was found that, although it was welcomed by staff, computerised monitoring played a secondary role in the clinicians' decision making (especially for junior and nursing staff) and that staff used the computer less often than indicated by self-reports. Factors that seemed to affect staff use of the computer were the lack (or shortage) of training on the system, the specific clinical conditions involved, and the availability of alternative sources of information. These findings have relevant repercussions for the design of computerised decision support in intensive care and suggest ways in which computerised monitoring can be enhanced, namely: by systematic staff training, by making available online certain types of clinical information, by adapting the user interface, and by developing intelligent algorithms.

Molybdenum cofactor-deficient mice resemble the phenotype of human patients

Human molybdenum cofactor deficiency is a rare and devastating autosomal-recessive disease for which no therapy is known. The absence of active sulfite oxidase-a molybdenum cofactor-dependent enzyme-results in neonatal seizures and early childhood death. Most patients harbor mutations in the MOCS1 gene, whose murine homolog was disrupted by homologous recombination with a targeting vector. As in humans, heterozygous mice display no symptoms, but homozygous animals die between days 1 and 11 after birth. Biochemical analyis of these animals shows that molydopterin and active cofactor are undetectable. They do not possess any sulfite oxidase or xanthine dehydrogenase activity. No organ abnormalities were observed and the synaptic localization of inhibitory receptors, which was found to be disturbed in molybdenum cofactor deficient-mice with a Gephyrin mutation, appears normal. MOCS1(-/-) mice could be a suitable animal model for biochemical and/or genetic therapy approaches.

The bicistronic MOCS1 gene has alternative start codons on two mutually exclusive exons

The bicistronic MOCS1 gene encodes two enzymatic activities that are necessary for the biosynthesis of the molybdenum cofactor (MoCo). Mutations in either of the two consecutive open reading frames are responsible for the majority of MoCo deficiency cases and result in a complementation group A phenotype. Two cDNA sequences have been described, which differ in the 5' sequence and encode for two forms of the protein MOCS1A with variable N-terminal sequences. We have reinvestigated the corresponding region by means of cDNA analysis and databank searches. This revealed three different splice variants, including two mutually exclusive first exons and a facultative intron. All three forms can be found in eight different human tissues in a constant ratio, which excludes tissue specificity of the different isoforms.

Concomitant Traumatic Coronary Artery and Tricuspid Valve Injury: A Heterogeneous Presentation

Blunt thoracic trauma resulting in both tricuspid valve rupture and coronary artery injury is uncommon, encompasses a large spectrum of presentations and, therefore, can be difficult to diagnose. This report illustrates the heterogeneous presentation and clinical course of two patients with such a combination of cardiac injuries. The patient with associated right coronary artery dissection developed progressive right ventricular failure over a 12-year period before successful surgical repair, whereas another patient with left anterior descending coronary artery thrombosis required urgent operation for acute right ventricular dysfunction and hemodynamic decompensation.

Non-replication of association between cathepsin D genotype and late onset Alzheimer disease

In two recent studies from Germany, a strong association was found between the allelic variant T of the amino acid substitution encoding polymorphism 224 C/T (A38V) in exon 2 of the cathepsin D gene (CTSD) and late onset Alzheimer disease (AD). Other studies from Europe and the USA revealed ambiguous results. Therefore, we performed an independent association study on CTSD and AD in a sample of 324 Caucasian patients from Germany, Switzerland, and Italy with late onset AD, and 302 non-demented controls. We could not confirm an association between CTSD genotype and AD, although there was a slight but not significant increase in frequency of the T allele and T carrier status in AD. Post hoc data analyses suggested that there might be a stronger effect of CTSD genotype on AD risk in males, and an interaction between CTSD and APOE genotypes in males but not females.

A mutation in the gene for the neurotransmitter receptor-clustering protein gephyrin causes a novel form of molybdenum cofactor deficiency

Gephyrin was originally identified as a membrane-associated protein that is essential for the postsynaptic localization of receptors for the neurotransmitters glycine and GABA(A). A sequence comparison revealed homologies between gephyrin and proteins necessary for the biosynthesis of the universal molybdenum cofactor (MoCo). Because gephyrin expression can rescue a MoCo-deficient mutation in bacteria, plants, and a murine cell line, it became clear that gephyrin also plays a role in MoCo biosynthesis. Human MoCo deficiency is a fatal disease resulting in severe neurological damage and death in early childhood. Most patients harbor MOCS1 mutations, which prohibit formation of a precursor, or carry MOCS2 mutations, which abrogate precursor conversion to molybdopterin. The present report describes the identification of a gephyrin gene (GEPH) deletion in a patient with symptoms typical of MoCo deficiency. Biochemical studies of the patient's fibroblasts demonstrate that gephyrin catalyzes the insertion of molybdenum into molybdopterin and suggest that this novel form of MoCo deficiency might be curable by molybdate supplementation.

Genetic association of a cystatin C gene polymorphism with late-onset Alzheimer disease

OBJECTIVE

To determine whether the cystatin C gene (CST3) is genetically associated with late-onset Alzheimer disease (AD).

DESIGN

A case-control study with 2 independent study populations of patients with AD and age-matched, cognitively normal control subjects.

SETTING

The Alzheimer's Disease Research Unit at the University Hospital Hamburg-Eppendorf, Hamburg, Germany, for the initial study (n = 260). For the independent multicenter study (n = 647), an international consortium that included the Massachusetts Alzheimer's Disease Research Center at the Massachusetts General Hospital, Boston; the Scientific Institute for Research and Patient Care, Brescia, Italy; and Alzheimer's research units at the Universities of Basel and Zurich, Switzerland, and Bonn, Goettingen, and Hamburg, Germany.

PARTICIPANTS

Five hundred seventeen patients with AD and 390 control subjects.

MEASURES

Molecular testing of the KspI polymorphisms in the 5' flanking region and exon 1 of CST3 and the apolipoprotein E (APOE) genotype. Mini-Mental State Examination scores for both patients with AD and control subjects.

RESULTS

Homozygosity for haplotype B of CST3 was significantly associated with late-onset AD in both study populations, with an odds ratio of 3.8 (95% confidence interval, 1.56-9.25) in the combined data set; heterozygosity was not associated with an increased risk. The odds ratios for CST3 B/B increased from 2.6 in those younger than 75 years to 8.8 for those aged 75 years and older. The association of CST3 B/B with AD was independent of APOE epsilon4; both genotypes independently reduced disease-free survival.

CONCLUSIONS

CST3 is a susceptibility gene for late-onset AD, especially in patients aged 75 years and older. To our knowledge, CST3 B is the first autosomal recessive risk allele in late-onset AD.

Genetics of molybdenum cofactor deficiency

Molybdenum cofactor (MoCo) deficiency leads to a combined deficiency of the molybdoenzymes sulphite oxidase, xanthine dehydrogenase and aldehyde oxidase. Effective therapy is not available for this rare disease, which results in neonatal seizures and other neurological symptoms identical to those of sulphite oxidase deficiency. It is an autosomal recessive trait and leads to early childhood death. Biosynthesis of MoCo can be divided into the formation of a precursor and its subsequent conversion to the organic moiety of MoCo by molybdopterin synthase. These two steps are the molecular basis of the two observed complementation groups A and B and of two types of MoCo deficiency with an identical phenotype. MOCS1 is defective in the majority of patients (group A) and was shown to encode two enzymes functioning in the formation of a precursor. The corresponding transcript is bicistronic with two consecutive open reading frames (ORFs). MOCS2 encodes the small and large subunits of molybdopterin synthase via a single transcript with two overlapping reading frames. This gene carries lesions in the B complementation group less frequently observed in patients. Both genes, MOCS1 and MOCS2, share the unusual bicistronic architecture, have identical and very low expression profiles and extremely conserved C-terminal ends in their 5'-ORF. These observations point to a novel form of microcompartmentalization and render the MOCS genes ideal candidates for a somatic gene therapy approach.

Prenatal diagnosis and carrier detection for molybdenum cofactor deficiency type A in northern Israel using polymorphic DNA markers

Molybdenum cofactor deficiency (MoCoD) is an autosomal recessive, fatal neurological disorder, characterized by the combined deficiency of sulphite oxidase, xanthine dehydrogenase and aldehyde oxidase. We have recently reported an excessive occurrence of this fatal disorder among segments of the Arab population in Northern Israel suggesting that the true incidence of MoCoD is probably underestimated in this highly inbred population. This lethal disease can be diagnosed prenatally by assay of sulphite oxidase activity in chorionic villus samples in pregnancies of couples who have had previously affected children (obligatory carriers). However, to date, there is no biochemical assay for carrier detection among the population at risk. Recently we demonstrated the linkage of a MoCoD gene to an 8-cM region on chromosome 6p21.3 in two consanguineous Israeli-Arab unrelated kindreds. The description of the MOCS1 gene that maps to the same region and which carries multiple mutations in MoCoD type A followed this finding. We describe here one additional kindred of Arab-Israeli origin, which is also linked to the MOCS1 locus, and demonstrate the feasibility of prenatal diagnosis and carrier detection using microsatellite markers in selected families when mutations are unknown. A complete correlation between the biochemical and DNA assays was found in a total of six samples (five chorionic villus and one amniocyte culture sample) obtained from the three MoCoD families.

[Hyperglycemia and ketoacidosis associated with olanzapine]

Two psychotic patients developed hyperglycaemia several weeks after starting olanzapine. In one case the elevated glucose concentrations returned to normal soon after withdrawal of olanzapine. In the second case severe ketoacidosis with lethal outcome occurred.

Use of molecular subtyping to document long-term persistence of Corynebacterium diphtheriae in South Dakota

Enhanced surveillance of patients with upper respiratory symptoms in a Northern Plains community revealed that approximately 4% of them were infected by toxigenic Corynebacterium diphtheriae of both mitis and gravis biotypes, showing that the organism is still circulating in the United States. Toxigenic C. diphtheriae was isolated from five members of four households. Four molecular subtyping methods-ribotyping, multilocus enzyme electrophoresis (MEE), random amplified polymorphic DNA (RAPD), and single-strand conformation polymorphism-were used to molecularly characterize these strains and compare them to 17 archival South Dakota strains dating back to 1973 through 1983 and to 5 isolates collected from residents of diverse regions of the United States. Ribotyping and RAPD clearly demonstrated the household transmission of isolates and provided precise information on the circulation of several distinct strains within three households. By MEE, most recent and archival South Dakota strains were identified as closely related and clustered within the newly identified ET (electrophoretic type) 215 complex. Furthermore, three recent South Dakota isolates and eight archival South Dakota isolates were indistinguishable by both ribotyping and RAPD. All of these molecular methods showed that recent South Dakota isolates and archival South Dakota isolates were more closely related to each other than to the C. diphtheriae strains isolated in other parts of the United States or worldwide. The data also supported the improbability of importation of C. diphtheriae into this area and rather strongly suggest the long-term persistence of the organism in this region.

Molybdenum cofactor deficiency: first prenatal genetic analysis

Molybdenum cofactor (MoCo) deficiency leads to a combined deficiency of the molybdo-enzymes sulphite oxidase, xanthine dehydrogenase and aldehyde oxidase. No therapy is known for this rare disease, which results in neonatal seizures and other neurological symptoms identical to sulphite oxidase deficiency. It is inherited autosomal-recessively and leads to early childhood death. Prenatal diagnosis has been performed since 1983 by the measurement of sulphite oxidase activity, but no enzymatic carrier diagnosis is possible. The human genes necessary for MoCo biosynthesis have recently been cloned and mutations in the bicistronic MOCS1 gene could be identified in most European patients. In a Danish family we have now performed enzymatic and molecular genetic analysis in parallel after chorionic villus sampling. The sulphite oxidase activity in uncultured CVS material was found to be normal. A MOCS1 splice site mutation, found homozygous in the affected patient, was found in a heterozygous state in cultured chorionic cells. This confirmed that the fetus was not affected, since heterozygous carriers of a MoCo deficiency allele do not display any symptoms.

Human molybdopterin synthase gene: identification of a bicistronic transcript with overlapping reading frames

A universal molybdenum-containing cofactor (MoCo) is essential for the activity of all human molybdoenzymes, including sulphite oxidase. The free cofactor is highly unstable, and all organisms share a similar biosynthetic pathway. The involved enzymes exhibit homologies, even between bacteria and humans. We have exploited these homologies to isolate a cDNA for the heterodimeric molybdopterin (MPT)-synthase. This enzyme is necessary for the conversion of an unstable precursor into molybdopterin, the organic moiety of MoCo. The corresponding transcript shows a bicistronic structure, encoding the small and large subunits of the MPT-synthase in two different open reading frames (ORFs) that overlap by 77 nucleotides. In various human tissues, only one size of mRNA coinciding with the bicistronic transcript was detected. In vitro translation and mutagenesis experiments demonstrated that each ORF is translated independently, leading to the synthesis of a 10-kDa protein and a 21-kDa protein for the small and large subunits, respectively, and indicated that the 3'-proximal ORF of the bicistronic transcript is translated by leaky scanning.

Human molybdopterin synthase gene: genomic structure and mutations in molybdenum cofactor deficiency type B

Biosynthesis of the molybdenum cofactor (MoCo) can be divided into (1) the formation of a precursor and (2) the latter's subsequent conversion, by molybdopterin synthase, into the organic moiety of MoCo. These two steps are reflected by the complementation groups A and B and the two formally distinguished types of MoCo deficiency that have an identical phenotype. Both types of MoCo deficiency result in a pleiotropic loss of all molybdoenzyme activities and cause severe neurological damage. MOCS1 is defective in patients with group A deficiency and has been shown to encode two enzymes for early synthesis via a bicistronic transcript with two consecutive open reading frames (ORFs). MOCS2 encodes the small and large subunits of molybdopterin synthase via a single transcript with two overlapping reading frames. This gene was mapped to 5q and comprises seven exons. The coding sequence and all splice site-junction sequences were screened for mutations, in MoCo-deficient patients in whom a previous search for MOCS1 mutations had been negative. In seven of the eight patients whom we investigated, we identified MOCS2 mutations that, by their nature, are most likely responsible for the deficiency. Three different frameshift mutations were observed, with one of them found on 7 of 14 identified alleles. Furthermore, a start-codon mutation and a missense mutation of a highly conserved amino acid residue were found. The locations of the mutations confirm the functional role of both ORFs. One of the patients with identified MOCS2 mutations had been classified as type B, in complementation studies. These findings support the hypothetical mechanism, for both forms of MoCo deficiency, that formerly had been established by cell-culture experiments.

The neurotransmitter receptor-anchoring protein gephyrin reconstitutes molybdenum cofactor biosynthesis in bacteria, plants, and mammalian cells

The molybdenum cofactor (Moco), a highly conserved pterin compound complexing molybdenum, is required for the enzymatic activities of all molybdenum enzymes except nitrogenase. Moco is synthesized by a unique and evolutionarily old pathway that requires the activities of at least six gene products. Some of the proteins involved in bacterial, plant, and invertebrate Moco biosynthesis show striking homologies to the primary structure of gephyrin, a polypeptide required for the clustering of inhibitory glycine receptors in postsynaptic membranes in the rat central nervous system. Here, we show that gephyrin binds with high affinity to molybdopterin, the metabolic precursor of Moco. Furthermore, gephyrin expression can reconstitute Moco biosynthesis in Moco-deficient bacteria, a molybdenum-dependent mouse cell line, and a Moco-deficient plant mutant. Conversely, inhibition of gephyrin expression by antisense RNA expression in cultured murine cells reduces their Moco content significantly. These data indicate that in addition to clustering glycine receptors, gephyrin also is involved in Moco biosynthesis and illustrate the remarkable conservation of its function in Moco biosynthesis throughout phylogeny.

Genomic structure and mutational spectrum of the bicistronic MOCS1 gene defective in molybdenum cofactor deficiency type A

Molybdenum cofactor (MoCo) deficiency is a rare and devastating disease resulting in neonatal seizures and other neurological symptoms identical to those of sulphite oxidase deficiency. It is an autosomal recessive disease and no therapy is known. Most patients harbour MOCS1 mutations, which are found in both open reading frames of this unusual gene encoding the first two enzymes required in the MoCo biosynthesis pathway, MOCS1 A and MOCS1 B, in a single transcript. We describe genomic details as a prerequisite for comprehensive mutation analysis. In an initial cohort of 24 MoCo deficiency patients, we identified 13 different mutations on 34 chromosomes, with a mutation detection rate of 70%. Five mutations were observed in more than one patient and together accounted for two thirds of detected mutations. These comprise the most frequent mutation, R319Q, which is restricted to England, two Danish/German mutations (one missense and one splice site mutation), a missense mutation found in England and Germany, and a "Mediterranean" frameshift mutation. All patients with identified mutations are either homozygous or compound heterozygous for mutations in either of the two open reading frames corresponding to MOCS1 A and MOCS1 B, respectively. This observation suggests the existence of more than the two previously described complementation groups in MoCo biosynthesis.

Effect of repeated bouts of short-term exercise on plasma free and sulphoconjugated catecholamines in humans

We tested the hypothesis that measurement of plasma catecholamine sulphate concentration after exercise reflects the overall activation of the sympathoadrenergic system during the whole period of repeated bouts of short-term exercise. A group of 11 male athletes performed two exercise tests at similar average power outputs consisting of three sets each. The tests either started with one set of three very intense sprints (95% of maximal running speed) followed by two sets of three less intense sprints (85% of maximal running speed; HLX) or vice versa (LHX). Similar mean areas under the curve of free noradrenaline (NA) during HLX and LHX [622 (SEM 13) v.s. 611 (SEM 14) nmol x l(-1) min) as well as similar mean heart rates [143 (SEM 9) v.s. 143 (SEM 8) beats x min(-1)] indicated comparable sympathetic activation during both exercise tests. Even so, plasma concentration of free NA was still significantly higher at the end of LHX than of HLX [35.7 (SEM 3.5) v.s. 22.5 (SEM 2.1) nmol x l(-1), respectively], i.e. when exercise ended with the more intense set of sprints. Plasma noradrenaline sulphate (NA-S) increased with exercise intensity showing higher mean increments after the first set of HLX compared to LHX [1.83 (SEM 0.42) v.s. 1.18 (SEM 0.29) nmol x l(-1); P<0.05]. However, after the end of HLX and LHX, increments in plasma NA-S were similar [4.52 (SEM 0.76) v.s. 4.06 (SEM 0.79) nmol x l(-1)], suggesting that NA-S response changed in parallel with the overall activation of the sympathetic nervous system during repeated bouts of short-term exercise. The results supported the hypothesis that measurement of plasma NA-S immediately after repeated bouts of short-term exercise reflects overall activation of the sympathetic nervous system during prolonged periods of this type of exercise.

Mutations in a polycistronic nuclear gene associated with molybdenum cofactor deficiency

All molybdoenzymes other than nitrogenase require molybdopterin as a metal-binding cofactor. Several genes necessary for the synthesis of the molybdenum cofactor (MoCo) have been characterized in bacteria and plants. The proteins encoded by the Escherichia coli genes moaA and moaC catalyse the first steps in MoCo synthesis. The human homologues of these genes are therefore candidate genes for molybdenum cofactor deficiency, a rare and fatal disease. Using oligonucleotides complementary to a conserved region in the moaA gene, we have isolated a human cDNA derived from liver mRNA. This transcript contains an open reading frame (ORF) encoding the human moaA homologue and a second ORF encoding a human moaC homologue. Mutations can be found in the majority of MoCo-deficient patients that confirm the functional role of both ORFs in the corresponding gene MOCS1 (for 'molybdenum cofactor synthesis-step 1'). Northern-blot analysis detected only full-length transcripts containing both consecutive ORFs in various human tissues. The mRNA structure suggests a translation reinitiation mechanism for the second ORF. These data indicate the existence of a eukaryotic mRNA, which as a single and uniform transcript guides the synthesis of two different enzymatic polypeptides with disease-causing potential.

Localization of a gene for molybdenum cofactor deficiency, on the short arm of chromosome 6, by homozygosity mapping

Molybdenum cofactor deficiency (MoCoD) is a fatal disorder manifesting, shortly after birth, with profound neurological abnormalities, mental retardation, and severe seizures unresponsive to any therapy. The disease is a monogenic, autosomal recessive disorder, and the existence of at least two complementation groups suggests genetic heterogeneity. In humans, MoCoD leads to the combined deficient activities of sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase. By using homozygosity mapping and two consanguineous affected kindreds of Israeli-Arab origin, including five patients, we demonstrated linkage of a MoCoD gene to an 8-cM region on chromosome 6p21.3, between markers D6S1641 and D6S1672. Linkage analysis generated the highest combined LOD-score value, 3.6, at a recombination fraction of 0, with marker D6S1575. These results now can be used to perform prenatal diagnosis with microsatellite markers. They also provide the only tool for carrier detection of this fatal disorder.